Spark-plug.



J. M. WATTS.

v SPARK nus.

APPLECATION F IL-ED AUGJB. I917.

Patented Feb. 5, 1918.

' IN vtNTM JA ME: 'mzwr/xv Warns Wh /5 J//% arr-32i- UNITED STATES PATENT, OFFICE...

JAMES MARTIN WATTS, F LOS'iANG ELES, CALIFORNIA;

srAnmrLuo.

Application filed August 13, 1,817.

To kill whom it may concern:

Be it known that I, J AMES MARTIN Werrs,

a citizen of the United. States, residing at Los Angeles, in the county of Los Angcles' and State of California, have invented new and useful Improvements in Spark-Plugs,

of which the following is a speci cation.

This invention relates to a spark plug for internal combustion engines.

It is the principal object of this invcnti ui to provide a park plug which may be readily assembled or dismantled, and which is signed with electrodes not liable to be .we corroded or short-circuited. by carbon do posits. V

Other objects will appear hereinafter. I

The invention is illustrated, by way of example, in the accompanying drawings in which:

Figure 1 is a view in side elevation illustrating the spark plug with which the present invention is concerned, with parts broken away to, more clearly disclose the elements ofzwhich it is composed.

Fig. 2 is a view in plan as viewed from the lower end of the plug, particularly disclosing the circular formation of the control electrode andthe annular spark gap.

Fig. 3 is a view in perspective illustrating; the central electrode as disussocieted from.

the other parts of the plug and further dis" closin the fragmentary portion. of the surrounding electrode.

Referrino more particularly to the draw ings, 10 indicates the metallic body portion of a spark plug which is formed with. a tubuylar lower extension 11 externally threaded to die mounted withina-bore in the end wall 5 112 of an engine 0 linder. An enlarged 4p flan e portion 13 is ormed around thebody i-of tl ieplug and is adepted to bear upon the boss-through which it is screwed. ,The top j' llfthe plug. is hexagonal to facilitate in. mountingit in position. A metallic ackfls-ihg washer is interposed, between the onge po.' n i' tl1e cylinder head. The lower tubular portion- 11 of'the plu communicates with 1 Iii-bore 14 of reduced iametersubstentially midwey' the length thereof. This bore, in turn,'communicates w' h an upper bore 15 whlchis partially threaded adjacent the upper e'nd of. the plug toreceiver. packing nut 16-. AA porcelain post 17 extends down- 'wardly through the center-of-the nut 16 and has a reduced end-portion which passes the bor'eli, the lower end terminct-' Specification of Letters Patent.

- while to cause the disk electrode '21 to beheld at the engine cylinder .will act Patcnted Feb. 5, 1918.

Serial No. 1B ,924.

ing within the lower 'tubulfar body of the plug; A. metallic gasket 18 is 'interposed. between the end of the nut 16 and a shoulder upon the porcelain is placed between the shoulder on the 0st and. the shoulder at the bottom of the re 15, to hold the post in'rigid relation to the body of the plug. A bore 19 extends substuntinlly throughout the length of the post '85 to receive the stem 20 of a disk electrode 21. The lower portion of this bore is enlarged to accomu'iodute shoulder 22 upon the stem 20, The shoulder is held in-position by means of jam nut 23 which is telescoped the upper end of the porcelain postand engages threads upon the upper extension of the stem. By thi means the disk electrode may he rigidly heldin position and the electrode and porcelain 0st separably :15 secured to each other. Suitable washers 24- for loching the join nut in positiouare inter posed between the nut and thee'n'dof the' porcelain post, thus holding the nut binding post nut 25 is usedto clamp do the electric wire in-position. As particularly shown in Fig. '1',fthe

members ill'e so arranged and assembled as a a point-directly within the tubular body por 8 tion 11 of the plug. .As this disk is soni whet smalier then the borefivi'thinthistnbir hugmrtion an annular spark gap 26 will b termed. In this manners nuximumspim lug suriuce will he provided between. I lectrodes and the danger of mis-fire gre reduced.

In. operation, the epperittus is asser'nbl by first passing through the body of the plug, thereafter-tho 55 porcelain post is placed upon -th'e stem.20-- and locked in position b the jain nut 23. The binding nut 25 may tli the threaded end of'the packing .nut 16 and. its washer 18 ha'vebeed tightened down within the body ofthe' plug, the device isassembled and ready for use.

In operation, a sperkwilljump from the disk electrode '21 across the annular. to the circular electrode edv formed by "the body should accumulate, the compression within E? toiloosen it, as

the atmosphere-end I cule'te back and forth a bond the; diskjand "11 through the annular spark-go; 26); V It will thus beacon that-t e sperkplng e- 4 1 portion 11 of the .plug.*-1u case carbo post, and a similar gasketv 60 rigid" the stem of the electrode 1i en be pll iicgd upo -i stern. Wh n thgp unnamed, men-e new new may be ma assembled we itaparts my be removed and replaced 7 ore, that'with the uee of; ir culdr central ele trode end an pi t me no fi 'mnm spark e flnylapifk filng he now known to me, iti'is nschangeoin the combineaenunn viifir e twnstm n en. mad y those skill out departing from the ep" tion. 4

it of my invem A spark iii eomprisin e'metitllj'c bod having-an imn 's'crewgthreegi upon itz. hiring a wrench seat 13 011 lowerfend end ite upper end mannin a bore exten fro inits lower end having Tet-second redu'ceil bore extending a shortdietance and having a third bore enlei-get! relative to the second bore and exten from its upperend and forming a ,ighoudena t its junction withihe second bore f heing'Bci-ew-threded from the upp end; a peeking in the thirdb'o'i'e against the when 3'1 the m with t against the s houl disk electrode fixed upon the to near the center :25

ehoulder, a porcelain post havin 'an endextending downwa'xdlyend fitting 1n the secand bore and having a shoulder fittinqlin the the packing and avin' I third bore against a reduced upper and forming a second shou der and having a l0ng'itlldlllll1 6lltlfll bore enlarged at its lower end and forming ;an-

internalehoulder, a' second. the eecond shoulder, a pnckm nut around the porcelain ost screw-seat 'in the upper end of the t ird bore against the second pecking, an electrode stem fitting in .eeid central bore and havin an enlargement fitti r in the central bore packing against an having a screw-threaded lower end of the stem and fitting loosely in the first bore 41 'em nut screw-seated upon the upper en 0 i the stem and ehnmhered to fit upon the upper end of the porcelain post, and a binding poet screw-seated upon the upper end of the stern and againstthe jam nut I In testimony whereof I have signed my name to this specification.

J. M. WATTS;

upper end, a 

